곡관의 곡률에 따른 전자기유량계 설치효과의 수치모사에 의한 특성 예측(충류)

임기원,최상류,정명균,Lim, Ki Won,Choi, Sang Kyu,Chung, Myung Kyoon 대한기계학회 1999 大韓機械學會論文集B Vol.23 No.11

An electromagnetic flowmeter, based on a magnetic induction principle; provides an obstructionless flowmeter that essentially averages the velocity distribution over the pipe cross-sectional area. To predict the installation effects, the flowmeter installed near $90^{\circ}$ elbow is simulated by using a commercial code FLUENT(ver. 4.48) for the laminar flow field and a code developed through this study for magnetic field. The installation effects of the flowmeter are estimated by varying a number of the dependent parameters such as the radius of the elbow(Rc=1D, 1.5D, 2D, 3D), the location, Reynolds number and the direction of electrodes plane(${\varphi}$). It was found that all these factors affect the performance of the electromagnetic flowmeter significantly. The longer installation distance from the elbow is not always optimal to minimize the error, and also there exists an optimal location to install the EMF for a minimum error. Especially the flow signal with the electrodes plane direction of ${\varphi}=45^{\circ}$ is shown to yield smallest measurement error regardless of the Reynolds number and the curvature of elbow.

전자기유량계의 설계 및 제작

임기원,Lim, Ki-Won 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.10

An electromagnetic flowmeter(EMF) was developed and its characteristics were compared with a commercial EMF. The developed EMF was designed as the 100 mm nominal diameter. A signal processing circuit was also developed for generating the magnetic field and converting the flow signal to flowrate and flow quantity. In order to obtain a more stable and reliable flow signal, the double magnetizing frequency was adopted for magnetizing the coil of the EMF. For the characterization of the developed EMF, the uncertainty of calibrator was estimated within $\pm$0.5 %. The evaluation procedure of the uncertainty followed the ISO Guide to the Expression of Uncertainty in Measurement. It was found that the flow signals between the electrodes were about $\pm$60-$\pm$300$\mu$V, which were sufficient for the discrimination of flowmeter and the protection of noise. The test results against the calibrator showed the good linearity in the range of 3 ㎥/h and 70 ㎥/h. A commercialized design of the EMF based on the current study will be technically more competitive in domestic and foreign market.

곡관의 하류에 설치된 전자기유량계의 유량신호 특성에 관한 실험적 연구(난류 유동)

임기원,Lim, Ki-Won 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.11

An electromagnetic flowmeter(EMF) essentially averages the velocity distribution over the pipe cross- sectional area, and the measured value is dependent on the velocity profiles. In this study, installation effects of 90$^{\circ}$long elbow(KS B 1522, ISO 3419) on the EMF characteristics was investigated. A commercial EMF was adopted and the distribution of magnetic field in the electrodes cross section was measured. In the experiment, the national flow standard system, of which measurement uncertainty was evaluated in accordance with ISO 17025 recommendation, was used fur characterization of EMF. The leading line has 150D long straight pipe to established a fully developed flow before entering into the elbow and the elbow was installed downstream of it. then the flowmeter was tested within 50 D from the elbow. The installation effects of the flowmeter were investigated by varying the mean velocity(Reynolds No.)in pipe section, the locations and the direction of electrodes plane.($\phi$) From the experimental results, we find the optimal conditions to get most accurate measurements. Generally, the deviations from the calibration value were less than 0.5 % in farther than 10D distance from the elbow and the direction of electrode plane. $\phi$ = 90$^{\circ}$yielded the smallest measurement deviation. These characteristics were shown consistently in turbulent region regardless of the mean Reynolds number.

기름 유량표준장치의 개발 및 측정 불확도에 관한 연구

임기원,최종오,Lim, Ki-Won,Choi, Jong-Oh 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.8

A national standard system was developed in order to calibrate and test the oil flowmeters for the petroleum field. A stop valve and a gyroscopic weighing scale were employed for the primary standard of the flow quantity. It is operated by the standing start and finish mode and the static weighing method. The model equation for uncertainty evaluation was based on the calibration principle of standard system. The sources of the uncertainties were quantified and combined according to the GUM(Guide to the Expression of Uncertainty in Measurement). It was found that the standard system had the relative expanded uncertainty of 0.04 % in the range of 18 - 350 ㎥/h. According to the uncertainty budget, the uncertainties of the fluid density and the volume of pipeline, which were temperature dependent, contributed 92% of final uncertainty in the oil flow standard system.

코리올리스 질량유량계의 유량측정에 영향을 미치는 인자에 관한 실험적 연구

임기원,이완규,Lim, Ki-Won,Lee, Woan-Kyu 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.12

Coriolis mass flowmeter(CMF), which can measure the mass flow directly, is getting rapid attention for the industrial and custody transfer purpose. In order to study the characteristics and the applicability of CMF, it is tested with the national flow standard system. Two types of sensing tube, U-type and straight type, are employed in the test. Water, spindle oil and viscosity Standard Reference Material whose viscosities are 1, 20 and, 67 $\textrm{mm}^2$/s, respectively, are studied. It is shown that the linearity of CMF is getting deteriorated as the fluid viscosity increases, which is due to the zero drift and the relaxation time of the fluid. To test its applicability in the case of high pressured gas, it is calibrated using compressed air, It shows 1∼l.6 % deviations compared to the calibration results using water. It concludes that the fluid velocity in CMF should be lower than the sonic velocity. In addition, the effects of the vibration from the pipeline and pump on CMF as well as the long term stability are studied.

파이프 프루버의 측정불확도에 관한 연구

임기원,Lim, Ki-Won 대한기계학회 2000 大韓機械學會論文集B Vol.24 No.10

A pipe prover is a flowmeter calibrator used in flow measurement field. Gravimetric and volumetric methods were applied to determine the basic volume of the pipe prover. Uncertainty of its basic volume measurement was evaluated in accordance with the procedure recommended by International Organization for Standardization. The combined standard uncertainty of determining the basic volume was estimated from the sensitivity coefficient and the standard uncertainty of independent variables. It was found that the uncertainties of the weighing and volume measurements have dominant influence on that of the basic volume determination. With the quantitative analysis of the sensitivity coefficient, the contribution of the each variable uncertainty to the combined standard uncertainty of the basic volume is shown clearly.

필라테스 운동이 여대생의 신체구성과 하지근력 및 척추 형태에 미치는 영향

황윤영(Hwang, Yoon-Young),박기덕(Pack, Gi-Duck),임기원(Lim, Ki-Won) 한국체육과학회 2013 한국체육과학회지 Vol.22 No.5

This study is to provide the preliminary data verifying Pilates effect analyzing the effect of the warm-up, exercise and warm-down were conducted for 50 minutes a day, three time a week and for ten week. Pilates exercises for female university students on their body compositions, changes in the spine and muscular strength. The study is to involve female university students, majoring in general department (non-Physical Education) who take liberal arts classes in K and N university, and it was distinguished between 9(PG: age(20.6±0.9), height (160.9±7.1), weight(53.9±4.5)) female university students who will participate in Pilates Exercise Program and 9(CG: age(22.2±1.4), height(159.9±5.4), weight(52.3±4.7)) female university students who won"t. First, There were insignificant differences in body composition factor. Second, There were significant differences in Peak torque from isokinetic muscular function factor, Total work and Average power. Third, There were insignificant differences in 3-dimension spine body type factor. Through the ten-week Pilates exercises for three times a week, there weren"t significant differences in the body composition and positive effect of isokinetic muscular function factor, and the 3-dimension spine body type was shown.

국가교정검사기관(액체유량)의 측정정확도 비교연구

임기원(KI WON LIM) 대한설비공학회 2000 대한설비공학회 학술발표대회논문집 Vol.2000 No.-

97년도 춘계학술대회 : 학술발표 : 운동과 식사제한이 체중조절에 미치는 영향

임기원(Lim Ki Won) 한국운동영양학회 1997 한국운동영양학회 학술발표논문집 Vol.- No.2

중년여성의 건강연령에 대한 한,일 비교

임기원 ( Ki Won Lim ),노호성 ( Ho Sung Nho ),이성노 ( Sung No Lee ),최성근 ( Sung Keun Choi ),( Kiyoji Tanaka ) 한국운동영양학회 2004 Physical Activity and Nutrition (Phys Act Nutr) Vol.8 No.1

Korea and Japan are close neighbor geographically, and have similar cultures, but different socio-economically. The purpose of this study was to compare health age in a wide age range between Korean and Japanese middle-aged women. The subjects were 220 (122 Korean and 98 Japanese) middle-aged women, aged 32 to 64 years. Eight items are related to health age were measured. The result of the comparison clearly indicated that Korean middle-aged women had a higher health age than Japanese middle-aged women (P<0.05), because Korean middle-aged women lowered the physical fitness compared with Japanese. From these results, it can be concluded that advancing age significantly for health age in middle-aged women of both countries, and that the lower health age reflects a lifestyle of more vigorous physical fitness in Japanese middle-aged women.